The long-term goal of the proposed research is to understand the role of K2P potassium leak channels in physiology. Despite unusually extensive regulation by chemical and physical stimuli, and a fundamental role in controlling excitability, relatively little is known about the function of K2P channels. The immediate goal of this work is to understand how the fatty acids arachidonic acid (AA) and lysophosphatidic acid (LPA) regulate KCNK2 and KCNK0. The three specific aims designed to address these goals are: (i) characterize the mechanism of KCNK2 activation by AA, (ii) identify the pathways involved in LPA modulation of KCNK2 and KCNK0, and (iii) study the relationship between fatty acid and stretch activation of KCNK2. The results of this research will provide insight into the function of K2P channels and may reveal new targets for anti-inflammatory therapy. Fatty acid modulation will be examined using expression in oocytes of wild type, mutant, or chimeric channels and patch clamp recording in the whole-cell or off-cell configurations. Mechanosensitivity of KCNK2 expressed in oocytes will be studied using patch clamp techniques and a pressure clamp amplifier in the cell-attached mode.